This is a control mirror where Mystical Dispute is exceptional, hard-countering their Counterspell, Day's Undoing, and other blue spells for as little as one mana. Consign to Memory adds more interaction, countering colorless spells and triggered abilities, which can pick off replicated triggers or other colorless permanents' abilities in a grindy control matchup. Galvanic Discharge is actually a strong include here since it can pick off Narset, Parter of Veils, Teferi, Time Raveler, and Teferi, Hero of Dominaria in addition to their lone creature Solitude, so it stays in. Spell Snare still has live targets in this matchup, since their Consult the Star Charts costs just {1}{U} for mana value 2, but with our counterspell suite already deep, trimming a copy or two makes room for the more impactful Mystical Dispute and Consign to Memory plan.